Musannaf Ibn Abi Shayba 13:1784

Abu Bakr narrated to us, he said: Ibn Abi Za’idah narrated to us, from Salih ibn Hayy, from ‘Amir, who said: The testimony of a Muslim man is permissible as long as he has not incurred a prescribed punishment (hadd) or a sin has been known upon him in his religion.